This nonprovisional application claims priority under 35 U.S.C. xc2xa7119(a) on patent application No. 91114673 filed in TAIWAN on Jul. 2, 2002, which is herein incorporated by reference.
1. Field of the Invention
The present invention relates to a method of determining the disconnection location of a circuit in an integrated circuit package and, more particularly, to a method of determining the disconnection location of a circuit in an integrated circuit package without destructing the physical structure of the integrated circuit package.
2. Description of the Prior Art
Along with the improvement of life quality and progress of science and technology, modern electronic products are made smaller and smaller to meet user""s requirements. In order to meet the requirement of size reducing for these electronic products, the density of conducting wires of electronic components in electronic products is increasing and the volume of electronic components is shrinking day by day. However, the density increasing of conducting wires also increases the difficulty in the manufacturing process of these electronic components as well as the testing process thereof. Therefore, how to improve the yield of the manufacturing process to ensure that signals can be transmitted intact between components and how to find the cause when an electronic component fails have become more and more important.
When a signal transmission problem occurs in a system composed of several electronic components, it is necessary to analyze and determine which electronic component has been failed and the where the failure location is, so as to find out the problem and help the manufacturers improve their quality control of the production process. Usually, there are two categories of analysis methods: the nondestructive failure analysis method and the destructive failure analysis method. In the nondestructive failure analysis method, the external appearance check and X-ray analysis are performed. Unfortunately, in the external appearance check approach, only the external appearance of an electronic component is roughly checked, and consequently, the location regarding where disconnection occurs is comparatively difficult to be recognized, so the X-ray analysis should be further performed. The X-ray analysis, is specific and limited to some local areas, thus is not suitable when it comes to finding out the accurate location of the disconnection in a whole component. Therefore, further advanced analyses for the electronic component cannot be performed on this occasion.
In the destructive structure analysis method, the structure of an electronic component is destroyed to check whether conductive wires are failed. Although this method directly reflects the situation of the destructed region; it may also destruct some other structure-lawless regions, resulting in misjudgment of the failure position of these failure components. In addition, it is also difficult to accurately destruct a predetermined region for observation. Moreover, when destructing several uncertain regions where we are not sure if any failure occurs, much time and resources will be squandered accordingly, and hence is not a good way for the manufactures to find out the location of disconnection in an electronic component.
The primary objective of the present invention is to provide a method of determining the disconnection location through comparing waveforms, whereby performing the so-called nondestructive analysis for the connection failure between components to determine the accurate position of disconnection.
Another objective of the present invention is to provide a method of determining the disconnection location through waveforms, whereby performing an analysis for a system consisting of several components to find out the flawed disconnection location in the system.
Another objective of the present invention is to provide a method of determining the disconnection location through waveforms so as to check the internal connection problem of a single component to determine the position of disconnection in the component.
According to a preferred embodiment of the present invention, a method of determining the disconnection location in a circuit, comprising the steps of: inputting a first signal into at least one standardized failed sample of said circuit that we have already known where the disconnection location is in said sample; receiving and storing a first reflected waveform of said sample for establishing a first reflected waveform model for said sample; inputting a second signal into a device under test (DUT) of said circuit; receiving and recording a second reflected waveform of said DUT; and comparing said second reflected waveform with said first reflected waveform model to determine a disconnection location in said DUT.
Moreover, said first and second signal can be a square wave, and said first and second signal has a rising/falling time ranging from 35 to 200 pico seconds. In addition, said first reflected waveform model is stored in a picture format. Said first and second signal can be provided and received by a time domain reflectrometer (TDR). The input position of the first signal on said standardized failed sample is the same as the input position of the second signal on said DUT. The input position of said first signal to said standardized failed sample is as same as that of a reflected signal emitted therefrom. The input position of said DUT for said second signal is the same as that of a reflected signal emitted from the DUT. When the reflected waveform of said, DUT is the same as or similar to a waveform in said, first reflected waveform model, said disconnection location is determined.
Further according to a second preferred embodiment of the present invention, in the method of determining the disconnection location in a circuit, said at least one standardized failed sample of said circuit comprises a plurality of standardized failed samples and said first reflected waveform model comprises the reflected waveforms of said plurality of standardized failed samples. When the reflected waveform of said DUT is the same as or similar to a waveform in said first reflected waveform model, said disconnection location is determined. When the reflected waveform of said DUT is similar to a first waveform in said first reflected waveform model, said disconnection location can be determined by corresponding a standardized failed sample to said first waveform. When the reflected waveform of said DUT is similar to a first and a second waveform in said first reflected waveform model, said disconnection location can be determined by corresponding a first and a second standardized failed sample respectively to said first and said second waveform.
The various objects and advantages of the present invention will be more clearly understood from the following detailed description when read in conjunction with the appended drawing, in which: